Apparatus and methods for purging flow cells in nucleic acid sequencing instruments

1. A method for operating a nucleic acid sequencing instrument having one or more movable flow cells, the method comprising:

providing a flow cell comprising a flow path having an inlet port and an outlet port;

filling the flow path, from the inlet port to the outlet port, with a first liquid reagent;

providing a station block having an inlet passage and an outlet passage;

mounting the flow cell on the station block to place the inlet port in fluid communication with the inlet passage and the outlet port in fluid communication with the outlet passage;

introducing a gaseous bubble into the inlet port by:

evaporating a portion of a second liquid reagent located in the inlet passage to create a gas space at a top end of the inlet passage prior to mounting the flow cell on the station block, and

capturing gas in the gas space upon mounting the flow cell to the station block to thereby form the gaseous bubble;

conveying a second liquid reagent from the inlet passage into the inlet port to move the gaseous bubble through the flow path and into the outlet passage and fill the flow passage with the second liquid reagent; and

removing the flow cell from the station block.

2. The method of claim 1 , wherein introducing the gaseous bubble into the inlet port further comprises conveying the second liquid reagent to the inlet port to move the gaseous bubble into the inlet port in advance of the second liquid reagent.

3. The method of claim 1 , wherein evaporating the portion of the second liquid reagent comprises heating the station block at a temperature of about 140° to about 150° degrees Fahrenheit for a period of about 7.5 to about 15 seconds.

4. The method of claim 1 , wherein providing the gas space at the top of the inlet passage further comprises conveying pressurized gas into the inlet passage prior to mounting the flow cell on the station block.

5. The method of claim 1 , wherein providing the gas space at the top of the inlet passage further comprises draining a portion of the second liquid reagent from the top of the inlet passage prior to mounting the flow cell on the station block.

6. The method of claim 1 , wherein providing the gas space at the top of the inlet passage further comprises pumping a portion of the second liquid reagent from the top of the inlet passage prior to mounting the flow cell on the station block.

7. The method of claim 6 , wherein pumping the portion of the second liquid reagent from the top of the inlet passage comprises removing the portion of the second liquid reagent with a variable-displacement chamber.

8. The method of claim 1 , wherein conveying the second liquid reagent from the inlet passage into the inlet port to move the gaseous bubble through the flow path and into the outlet passage and fill the flow passage with the second liquid reagent comprises operating a suction pump located downstream of the outlet passage.

9. A method for operating a nucleic acid sequencing instrument having one or more movable flow cells, the method comprising:

providing a flow cell comprising a flow path having an inlet port and an outlet port;

providing a first station block having a first inlet passage and a first outlet passage;

mounting the flow cell on the first station block to place the inlet port in fluid communication with the first inlet passage and the outlet port in fluid communication with the first outlet passage;

pumping a first liquid reagent from the first inlet passage into the inlet port to fill the flow path with the first liquid reagent;

removing the flow cell from the first station block;

providing a second station block having a second inlet passage and a second outlet passage;

mounting the flow cell on the second station block to place the inlet port in fluid communication with the second inlet passage and the outlet port in fluid communication with the second outlet passage;

introducing a gaseous bubble into the inlet port by:

evaporating a portion of a second liquid reagent located in the second inlet passage to create a gas space at a top end of the second inlet passage prior to mounting the flow cell on the second station block, and

capturing gas in the gas space upon mounting the flow cell to the second station block to thereby form the gaseous bubble;

pumping a second liquid reagent from the second inlet passage into the inlet port to move the gaseous bubble from the inlet port to the second outlet passage and to fill the flow path with the second liquid reagent; and

removing the flow cell from the first station block.

10. The method of claim 9 , wherein introducing the gaseous bubble into the inlet port further comprises pumping the second liquid reagent to the inlet port to move the gaseous bubble into the inlet port in advance of the second liquid reagent.

11. The method of claim 9 , wherein evaporating the portion of the second liquid reagent comprises heating the second station block at a temperature of about 140° to about 150° degrees Fahrenheit for a period of about 7.5 to about 15 seconds.

12. The method of claim 9 , wherein providing the gas space at the top of the second inlet passage further comprises conveying pressurized gas into the second inlet passage prior to mounting the flow cell on the second station block.

13. The method of claim 9 , wherein providing the gas space at the top of the second inlet passage further comprises draining a portion of the second liquid reagent from the top of the second inlet passage prior to mounting the flow cell on the second station block.

14. The method of claim 9 , wherein providing the gas space at the top of the second inlet passage further comprises pumping a portion of the second liquid reagent from the top of the second inlet passage prior to mounting the flow cell on the second station block.

15. The method of claim 14 , wherein pumping the portion of the second liquid reagent from the top of the second inlet passage comprises removing the portion of the second liquid reagent with a variable-displacement chamber.

16. The method of claim 9 , wherein pumping the second liquid reagent from the second inlet passage into the inlet port to move the gaseous bubble through the flow path and into the outlet passage and fill the flow passage with the second liquid reagent comprises operating a suction pump located downstream of the outlet passage.

17. The method of claim 9 , wherein the steps of pumping the first liquid reagent and pumping the second liquid reagent comprise operating a single suction pump that is fluidly connected to the first outlet passage and the second outlet passage.